Agent for accelerating vulcanization of rubber and method of producing same



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STAHLEY J GEN EEACEEY, ill-l3 Lill lllfihl', iiihi'GLhNfl).

AGENT FQR AfiGELERATING VULQAEIZATIQN 0 F 33 1733333 AMI) METHGD CF YBODUC- 1 ENG- SAEKE.

No Drawing. original epuiiestion flied Sol 15 1918 Method of Producing Some, of which the following is e specification.

This invention is s division of epplicetion, Serial No. 245097, filed July-15th, 1918, and refers to and consists of {1) new agents for accelerating the vulcanization of rubber or rubbculike substances by sulphur, (2-), 21 method of producing such agents, and (8) the use of such e ents in the vulcanization of rubber by sulp iur.

According to 'the invention, the new u cuts are produced by subjecting a mixture 0 o pornnitroso dimethylanilme homologue and sulphur to heot, whicli (muses a. vigorous reaction resulting in two products being obtained, either of which on being added to rubber prior to vulcanization will serve to nccelerete the vulcanization.

in carrying out the invention, the homologos of psrenitroso diinethyiuniline for example osrenitroso diethyloniline is mixed with sulphur in quantities corres Jonding to one molecular proportion of the oniologue and from one to two atomic proportions of sulphur, or in proportions differing from these 'accordin to the physical nsture and condition Whic the product, or one of the products, is desired to possess, for example,-

a considerable excess of sulphur may be employed in order to obtain at product contein ing free sulphur and one which will readily grind to powder, or less sulphur may he emplayed, when a more resinous product is obtained, which may contein tree nitroso compound. The ultimate products possess occelereting action due to the presence of the new agent or agents; The mixture of the homologue of perenitroso dimethyleniline and sulphur in the proportions stated is hosted to a. temperature of about 130135 (1., or thereeboute, whereupon e. vigorous rogction takes iece resultin in the eyolution of dense rcdoish coloured lunies, which condenses on cooling to e yellowish red sub- Serial No. $645,697. Divided and this application filed Serial No. 591,325.

stance. The residual substance left after the reaction has completed itself is a dark Both the yellowsi is melted in :3. suitable vessel heated to the 1 reacting temperature, and the paronrtroso compound is added in small portions at s. time with stirring. As soon as the vigorous reaction produced by such addition subsides, a fresh portion is added and so on until the whole of the nitroso compound has been introduced. By using the sulphur in considerable excess of the amount required for the reaction, a residual product is obtained which presents the appearance of a herd (lurk coloured resin which is readily reduced to a fine powder.

Using an open vessel for the above operation the red fumes are of course dispersed, but the residual mixture contains the brown resinous product and constitutes in most useportion of perenitroso compound reaction takes place to a. certain extent on heating but the product then contains uppreciebie amounts of free perenitroso compound, which is undesirable in that this free nitroso base possesses objectionable staining properties, Whereas-one of the objects of this invention is to provide a product which is free from unchanged perenitroso base and therefore does not stain.

The following examples serve to illustrate the recesses referred to above, but I do not con me myself to the proportions stated as these may be varied considerably without dc 'nrting from the invention:

i jxsmple 1: 1?.8 parts by Weight or phur are melted in a ,to add either Mei - ployed for the acceleration of vulcanization.

Example 2: '15 parts by weight of suldish, the temperature raised to 13i-l35 Q, or thcreabouts, and paranit-roso diethylaniline is introduced in small quantities at a time with stirring until an amount. equal in Weighs to the sulphur has been added. Dense reddish coloured fumes escape and are lost (alihough means be devised for condensation if desired).

The. residual product forms on cooling; a hard brittle resin, which powders easily and forms a useful accelerator of vulcanization.

In applying; the new agenis as accelerators of the vulcenizing process, the procedure is of the new agents in appropriate quantityto the rubbermixture prior to vulcanizutiom and then to heat the mixture to the vulcanizing temperature by any of thowell known methods, when a Well vulcanized rubber is obtained in a for shorter time than is the case when the ac-- celerating agent is absent. -If desired, allowance may be made for any free sulphur present in the accelerator and this may be deducted from the amount of sulphur added to the mixture.

As examples of proportions the following are given, but I do not confine myself to the proportions specified variations may be made therein Without departing from the invention:

100 parts by Weight; of pianiation rubber.

10 parts by Weight of sulphur.

0.5 parts of either of the products obtained according to the direction previously given in Example 1.

The mixture is heated to a temperature corresponding to a steam pressure of from 40 to lbs, when perfect vulcanization is obtained in about 30 to 40 minutes, a much. shorter period than is required in the ordinary way; that is, Without the addition of the accelerating agent.

100 parts by weight of Parzi' rubber.

10 parts by Weight of sulphur.

l to 1.5 parts by Weight of the residual product obtained according to the direction given in Example 2.

The mixture is heated to a temperature corresponding to a steam pressure of from it) to 4:5 lbs". when vulcanization is com- The mixture is heated for Etc 3 hours at a temperature corresponding to a steam pressure of 40 0.50 lbs. and a durable hard rubber is thus obtained in about one-third to one-half. of the time normally required.

In my 'formerPatent No. 1,157,177 paranitroso dimetn laniline or a homolo ue of parunitroso dimethylaniline was useddirectly as an accelerator or the vulcanizin'g process. In my present. invention a homologue of paranitroso dimethylanilinc is used, but instead of being used as such is previously converted by heating with sul phur into a new compound or compounds, possessing acceleraiing properties, and also possessing the important advantage that, unlike paranitroso dimethylaniline and its homologues, it or they are free from objec- H tionable staining properties.

What I claim is: n v

1. Materials or agents for accelerating the vulcanization of rubber or rubber-like substances consisting of the condensate pro- .ducod by heating together a paranitroso dimethyianiline homologue and sulphur to a temperature at which interaction takes place, substantially as described.

2. Materials or agents for accelerating the vulci'nization of rubber or rubber-like substances consisting of the condensate produced by heating together a. paranitroso climethylaniline homologue and temperature of approximately l3 0135 ll, substantially as described.

'aterials or agents for accelerating the vulcaniza cion of rubber or rubber-like substances consisting of the condensate produced b heating together a. paranitmso dif'lbtlly aniline homologue and sulphur in quantities approximating to one molecular proportion of the homologue and two atomic proportions of sulphur, substantially as described.

Materials or agents for accelerating the vulcanization of rubber or rubber-like substances consisting of the condensate produced by heating together a paranitroso dimethylaniline homologue and sulphur in quantities approximating to one molecular proportion of the homologue and two atomic proportions of sulphur to a temperature of approximately 130-135 C., substantially as described.

5. Materials or agents for accelerating the vulcanization of rubber or rubber-lil e substances consisting oi the non-volatile residue ics sulphur to prnduce-i hmi-ing wgathfir pammitmw cizimtathyianiiine homaicogue: and sufqgfimy &0 a. temperatum at which inmmctien takes place, substantially as describec'i.

6. Matmials 0? agents 5 x: accelerating the vulcanizafian 0f rubmr mmbbex*-ika substancas consisting of the. nsmwoiatiia residue produced by heating izagether a pax'mifimsm dimethylamline homaiegue ami suhufit a iempezrature 11E wprmaimafimiy 13Q-135 Uz substaniaily @mflbafi.

a. lwtlatermls or agents for accelamting the: vulcanizatien Sf F'Lihbfif 0r rubber-like sussmnces ssnsiscing a? the nonwolafiile msirius fgradszced by heaiing mgether a, pamniimse dimethyianifim Ewmdogme and Sui-phi in quantities 5913mm w @m moiacztim E3: E oi sulphur, subsitmtmily as dig? 8. Mawrials or agents fer accelarating fihe I vulcanization of rubber 1 rubbeY-like substances consisting of the non-volatile residue pmduced by heating together a paranifirosa dimethyismiiine homelogue and sulphm" in quantities approximating to one moleculm: pmportion of the homologue and two atomic pmportions of sulphuric a, tempe'at ure of appmximat ly 130"-l$5? (3., substantially as descrihed.

in testimony wngreef 1 ham signsc; my name ta this specification 

